Safety standards require that any part of a telephone set or terminal which is accessible to the hand without requiring a tool should not be subject to an electrical potential dangerous to the user. In ordinary telephone sets, this condition can be met by providing housings which can be opened only by using tools, by employing screws or locking studs which cannot be undone without a screwdriver. In some telephone terminals which require a housing with a cover to receive a battery or a cassette for a telephone answering machine, for example, the cover is still secured by screwed locking means, but this is inconvenient for the user who does not always have a screwdriver available when a battery or cassette needs changing.
The object of the present invention is to ensure the electrical safety of a telephone set or terminal of the type having a housing with a cover to allow a removable component to be fitted, without sacrificing convenience of manipulation by the user.